Valve-grinding machine



1 G. LEMAY VALVE GRINDING MACHINE Oct. 23, 1934.

-' Filed Oct. 27, 1932 3 Sheets-Sheet 1 III Afforngy.

Oct. 23, 1934. G. LEMAY VALVE GRINDING MACHINE Filed Oct. 27, 1932 3Sheets-Sheet 2 Oct. 23, 1934. G. LEMAY V LVE GRINDING MACHINE 5Sheets-Sheet 3 Filed Oct. 27, 1932 HI [Wen/i521 dzwim/e 56%?- Affornq y,

Patented Oct. 23, 1934' PATENT OFFICE VALVE-GRINDING MACHINE- GustaveLemay, La Courneuve; France Application October 27, 1932, serial No.639,876 In France October 28, 1931 r 1 Claim. (01. 51-we l My inventionhas for its object a machine for grinding valves set at any angle. Myimproved machine also provides means for trimming with a diamond thevalve grinding wheels, for sharpening the cutters used for, machiningthe valve seats and for grinding the inner and outer surfaces of smallparts.

The chief features of my improved machine are the following: Its frameis semi-curved and its base stretches widely beyond the operative parts,forming thus a bed with no gap therefor and providing for themachineperfect steadiness and rigidity which are obviously the necessaryconditions for a proper grinding operation. The

motor embedded at the centre of the frame provides steadiness for thewholemachine and is protected against the metalparticles producedthroughthe grinding. Moreover its location allows the differenttransmission means to be disposed inside the frame, which does away withthe necessity of pulleys and belts outside the machine. At the sametime'I obtain thus a vertical traction on the wheel-carrier, which isthe,

most rational method of controlling a grindingwheel. The motor-shaftcarries a double pulley for controlling on one hand the-wheel and on theother a transmission controlling -i n its turn the vertical shaftactuating the sleeve of the special chuck holding the valve to beground. The end of the transmission shaft may carry means for driving ayielding transmission controlling a wheel system for grinding valves, devices for boring holes, for removing the scale from the valve stem orthe like operations.

The valve-holding chuck comprises three jaws the movements of which areperfectly equal whereby the valve may be held with its axis properlycentered and without any possibility of vibration.

The rigid large-base carriage affords means for transverse movementwhile the wide and rigid valve-carriage affords means for longitudinalmovement. Its head is centrally controlled from the pivoting basethrough a helical pinion whereby said head need not be overhung.

I have shown in accompanying drawings by way of example, a form ofexecution of my invention.

Fig. 1 is a front view of the machine, partly cross-sectional.

Fig. 2 is a side-view.

Fig. 3 is a plan view partly sectional.

Fig. 4 is a cross section along line IV-IV of Fig. 1.

Fig. 5 shows the means for mounting the diamond-carrying ring used forgrinding the wheel.

Fig. 6 is a longitudinal cross-section of the valve-holding chuck.

Fig. 7 is a view in a plane perpendicular to that of Fig. 6 of the partsinside the chuck, the outer driving sleeve of which has been removed.

Fig. 8 is a cross-section along line VIIIVIII. of Fig. 5.

" Fig. 9 is a cross-section along line IX--IX of Fig. 5.

Fig. l0"is a longitudinal cross-section of a modification.

Fig. 11 is a cross-section thereof along line XI-XI of Fig. 10.

The machine executed according to my invention comprises in the firstplace a framed wherein is housed the electric motor b. On the upper partof the frame is disposed the carriage c on which lie the roller bearingsfor the spindle d of the wheel e. This carriage is adapted to movetransversely along the slide f formed on the frame, under the action ofany known or suitable means. In front of the grinding wheel e isarranged the chuck g adapted to hold the valve to be ground. This chuckmay be directed in any desired direction with reference to its supportIt adapted to slide longitudinallyalong the slide 2' formed on theframe. The chuck is set in the desired direction through the pivot 7'1formed on the chuck holder 7'. This pivot is adapted to rotate in acircular recess provided in the support h. The chuck is locked. in thedesired direction through the bolt It. Through this pivot 7'1 and alongthe axis thereof passes the vertical spindle Z the upper end of whichcarries a worm m meshing with a helical toothwork n on the chuck g. Thelower end of the spindle l carries a pulley 0 controlled by a belt 10passing over the transmission shaft q along which it is adapted toslide. This transmission shaft is controlled in its turn through thebelt r actuated by the pulley s on the motor shaft. To the latter isalso keyed another pulley t actuating through a yielding belt u. and apulley v, the wheel spindle d.

The Whole control device described is arranged inside the frame a whichis entirely closed except for the opening a: admitting air to the motor.

When it is desired to make use of the machine for trimming the grindingwheel, the diamondcarrying ring a is fitted to the rear of the chuckholder as shown in Figs. 4 and 5. In this case the chuck holder isbrought through its direction controlling means in the direction opposedto that used for normal operation.

The chuck used in the machine comprises an outer sheath g which isdriven as explained hereinabove by the motor of the machine. This sheathis constituted by a hollow cylinder the front of which forms afrustocone g1. The three jaws 2 arranged in three equidistant radialplanes slide along the inside of this frustocone through the obliquesurfaces 2a forming the outside of one end of the jaws. These jaws 2.extending parallel to the axis of the chuck are provided at their endswith inner gripping parts 34 and at the end opposed to the obliquesurfaces 2a with reversely sloping surfaces 21) bearing against theinside of the frustoconical recess 5a provided in the thrust ring 5.These jaws are spaced'one with reference to the other by the jaw-spacingparts 6 secured each through a screw '7 to the frustoconical front endg1 of the chuck sleeve.

Inside the ring 5 may slide axially the hollow push-rod 8 urged by thespring 9 to move towards the front of the ring 5 and to bear against therear end 20 of the three jaws, which end is cut perpendicularly totheaxis of the chuck, A nut 10 screwed over the rear end of the push-rodprevents its falling out of the ring 5 while the chuck is being mountedor dismantled. The push-rod which serves to bear against the three jawswith an equal pressure provides a perfectly accurate simultaneity ofmotion of the three jaws whereby the centering of the valve held by themis always perfectly true.

The jaws 2 may slide between the spacing parts 6 and are held or urgedbackwards and outwards against the action of the spring 9, each by aspring 11. These springs 11 have one end 11a secured in one spacing partand extend freely through the free space to the side of this part intothe hole 12 provided in the corresponding law.

The thrust ring 5 is held down by the locking ring 13 screwed inside thesheath g.

The stem of the valve to be ground is disposed along the axis of thechuck between the jaws 222, after which the locking ring 13 is screwedinto the sheath 9 until the gripping parts 3-4 of the jaws bear againstthe periphery of the rod. This is provided by the action of the lockingring 13 on the thrust ring 5 which is thus caused to engage through itsfrustoconically recessed end 5a the sloping rear ends 2b of the jaws 2and to bring these ends nearer the axis. At the same time the jaws,urged forwards by the pushrod 8, slide through their slopingsurfaces 2aalong the inner conical surface of the frustoconical front end 9, of thechuck whereby the front ends of the jaws are also brought nearer theaxis of the chuck.

The slopes given to the ends 2a and 2b of the jaws being the same, theelastic pressure exerted by the end 8a of the push-rod 8 on the rearends of the jaws 2 which are perpendicular to the axis will move thesaid jaws 2 towards the axis through perfectly equal amounts, while thejaws remain perfectly parallel to their original position. This ensuresa perfectly true centering of the valve stem and allows the chuck tohold stems the diameter of which varies inside very wide limits.

This movement of the jaws is made against the action of the springs 11the yielding portion of which is deflected towards the front and towardsthe axis. Therefore, when the ring 13 is unscrewed, the springs act,through their elasticity, on the jaws which are thus brought back totheir starting position gradually as they are released by the thrustring and its push-rod 8.

Figs. 10 and 11 illustrate a modification wherein the jaws are urgedtowards one another by a conical spring 14 one coil of which passesthrough each jaw. Thus this coil deformed by the advance motion of thejaws when the locking ring is screwed down returns through itselasticity, the jaws into their starting position when the ring isunscrewed again.

What I claim is A valve grinding machine comprising a motor, a grindingwheel, a vertical pivot, a spindle passing axially through said pivot, aworm at the upper end of the said spindle, a chuck sleeve adapted torotateround a horizontal axis and carried by the pivot, a helical gearon said sleeve operatively engaged by the worm, a plurality ofequidistant jaws having outwardly frustoconical ends, said jaws beingadapted to slide inside the sleeve, a thrust ring, frusto-conical guidesfor the jaws, integral with the sleeve and with the ring respectively,yielding means urging said ring against the rear end of the jaws formoving the ends of the latter axially and radially along their guidesthrough equal distances, means for controlling the thrust ring, yieldingmeans urging the jaws back into their starting position, an idler shaft,a first belt between said motor and grinding wheel for rotating thelatter, a second belt connecting the motor to said shaft for revolvingthe same, and a third belt between said shaft and spindle fortransmitting a rotary movement thereto.

GUSTAVE LEMAY.

